TRANSGENIC/KNOCKOUT MOUSE SHARED RESOURCE: PROJECT SUMMARY/ABSTRACT Genetically engineered mouse models (GEMMs) have become indispensable tools in cancer research, with their utility ranging from studies of the basic biology of tumorigenesis and progression to the creation of genetically accurate tumor models for the evaluation of novel therapeutic approaches. The overall objective of the Transgenic/Knockout Mouse Shared Resource (TG-KO) is therefore to facilitate timely and cost-effective production and use of GEMMs in cancer research by members of the Virginia Commonwealth University (VCU) Massey Cancer Center (MCC). This objective will be met by producing novel GEMMs (including transgenic, knockout, conditional knockout and knock-in mice) using both conventional and CRISPR/Cas9- based technologies and by providing a full range of support services to facilitate the use of these models, including breeding colony management, mouse genotyping, mouse line rederivation, embryo and sperm cryopreservation and cryorecovery, and consultation. The TG-KO is directed by Jolene Windle, PhD, who has nearly 30 years of experience in the production and use of GEMMs in cancer research, and is supported by 2.5 additional FTEs who bring added expertise in GEMM creation, molecular methods involved in GEMM production and screening, and breeding colony management. The TG-KO is a jointly managed (MCC and VCU) resource that is within close walking distance of MCC member laboratories. The TG-KO facility includes restricted-access laboratory and animal holding space in the barrier vivarium in the Molecular Medicine Research Building, as well as general molecular biology laboratory space on the floor below, all of which is fully equipped for the services provided. The TG-KO does not have fixed hours of operation; however, a subset of staff members is generally present from 8:30 AM until 6:00 PM or later, Monday through Friday. All members of the staff can be readily reached by email, and they typically respond to emails from investigators as soon as possible, often outside of regular work hours. The services provided by the TG-KO are tracked and charged back. Additional support is provided by institutional sources and the Cancer Center Support Grant, which allows the TG-KO to offer its services at rates that are significantly lower than those charged by commercial vendors. The services provided by the TG- KO add value for MCC research by providing necessary services that are not practically obtained or are cost prohibitive through alternative vendors, including other non-profit institutions. Through the combination of in- house expertise and services and highly competitive rates, the TG-KO greatly facilitates the use of GEMMs by MCC members in their basic and translational cancer research efforts. In CY2015 TG-KO provided services to 18 MCC members, corresponding to 64% of the user base and 67% of all recharges.